The present invention relates to a rotary press with a rotary driven matrix table holding matrixes and with bottom and top dies. During rotation of the matrix table, these dies move in their axial direction towards and away from each other and press injected moldable material in boreholes of the matrix.
With known conventional rotary presses of this type, ordinarily normal stampings (blanks) of uniform thickness, particularly tablets, are produced. Solid top and bottom dies are being used. The press pressure is applied from one or both sides. With solid tablet-shaped stampings (blanks) a homogeneous compression (increase in density) is obtained when the known rotary presses are used.
When, however, profiled stampings or extrusions are to be produced which might be cup-shaped, for example, one must use profiled dies. Due to different press paths in the area of the walls and in the area of the bottom of the cup-shaped blank, different densities result. A desired homogeneous compression (increase in density) cannot be achieved. This is a considerable disadvantage with industrial blanks since there a high degree of precision with uniform material density, i.e., homogeneous compression throughout the entire cross-section of the blanks, must be achieved. Examples of such blanks are insulators for electrical articles which are made of ceramic material, for example aluminum oxide.
It is already known in the art how to manufacture such parts on mechanical or hydraulic presses (eccentric presses) which operate with split (divided) tools. In each case, only one top and one bottom tool is used so that with relatively high speeds of these presses, only a small production of blanks per unit time is possible.
It is, therefore, an object of the present invention to improve rotary presses of the initially mentioned type in such a way as to make possible the manufacture of profiled blanks of uniform material density throughout the entire cross-section with a high number per unit time.
Another object of the present invention is to provide an improved rotary press of the foregoing character which is substantially simple in construction and may be economically fabricated.
A further object of the present invention is to provide a rotary press, as described, which may be easily maintained and have a substantially long service life.